Genus Cothurnia Ehrenberg, 1831

Diagnosis. Circular anterior opening in top view, edge lacking outgrows. Short stalk, cylindrical, without folds, mesostyle and endostyle both absent; stalk sometimes with longitudinal striae. One or two small zooids present per lorica. Contractile vacuole small, at peristomial region. Macronucleus straight, pellicular striations inconspicuous (Fig. 4B, C) (Warren & Paynter 1991; Lynn & Small 2000).